ANGAL DO BARRO VERMELHO, Brazil — The nearest telephone is 19 miles away, and television arrived only in 1998. For generations, communities of poor blacks like this one, people descended from slaves who had run away from their masters during Portuguese colonial times, have existed in wary seclusion deep in Brazil's trackless backlands.

But now, more than a century after slavery was abolished in Brazil, these settlements that hint of Africa, known as quilombos, are hesitantly emerging from their traditional isolation and poverty.

With the encouragement and support of the Brazilian government, they are now pressing for legal title to ancestral lands and reaffirming their threatened culture.

Long neglected by the rest of Brazil, the quilombos have been facing extinction as the modern world closes in on them. Improved road, river and rail links have made their once remote fields valuable to ranchers, mining companies and land speculators, who have been seeking to dislodge them and seize village lands for commercial development.

"We have been here for 300 years, resisting as best we can, but until recently no one paid us any heed, because we were black and poor and didn't even know that we had any rights," said Carlos Alberto Gomes, a leader of this community of 110 families on the banks of the São Francisco River. "But these are fertile lands on which you can grow anything, and so people covet them now." In total, 724 quilombos, some dating back as far as the 17th century, have been identified across Brazil and are seeking formal recognition of their status.

The largest single concentration of such communities, 259, is here in the northeastern state of Bahia, which has the country's highest percentage of black residents, followed by the Amazon states of Pará and Maranhão.

"When we started out, we thought there would just be a few isolated cases," said Cláudio Braga, an official of the National Land Reform and Colonization Institute in Brasília who deals with the quilombos. "As people have overcome their shame at saying they are descendants of fugitive slaves, the numbers have grown surprisingly."

Indeed, quilombos — the word quilombo means encampment or forest settlement in various West African languages — have been found in settings as diverse as mountains, jungles and arid scrubland.

"They went wherever the geographical barriers were the greatest, so that whites wouldn't go there after them," Mr. Braga explained.

At first glance, quilombos like this one, whose name means red clay mangrove thicket, seem indistiguishable from any other poor village in the Brazilian interior. The lone school offers classes only up to fourth grade, the single road is a rutted dirt path and "the closest medical care is an 11-mile boat ride away," said Egídio Gomes Pereira, a community leader.

But the words commonly used here and in nearby quilombos for such everyday concepts as house, spoon, straw and grandparents are derived from West African languages like Yoruba. Houses in some communities are arranged in what is said to be West African style, in a circular fashion around a central space. Though most residents are nominally Catholic, their religious ceremonies and festivals contain elements that anthropologists and sociologists say are traceable to African practices even more strongly than those of other black Brazilians.

"The African elements are there, but the people have always had a certain timidity about considering their historic culture as something positive," said Valdélio Santos Silva, director of the sociology department at the State University of Bahia in the nearby town of Bom Jesus da Lapa and a leader of the United Black Movement. "Until recently they've been treated as if they were worthless, so they have learned to hide their culture from outsiders."